The circulation of Galileo’s prohibited books during his lifetime

Galileo Dialogo lettera manoscritta.jpg

This interesting manuscript letter, written in 1641, is a striking testament of the difficulties and dangers involved with finding a copy of Galileo’s Dialogo as early as 9 years after its publication in Florence in 1632.

The ‘Dialogue on the Two Chief Systems of the World’ is universally considered to be Galileo’s scientific and literary masterpiece. The use of dialogue form allowed Galileo to cast the work as a hypothetical discussion and thus to explore the Copernican model without breaking the parameters imposed by the pope. The censors were easily deceived and in 1630 the book received an imprimatur. Nevertheless, in 1633 Galileo’s enemies dragged him to Rome, where he was tried in front of the Inquisition and forced to abjure, and the Dialogo was entered into the Index, where it remained listed until 1757. Condemned to life imprisonment, the sentence was then commuted to permanent house arrest.

The Dialogo was not included in the first and second editions of Galileo’s collected works (published, respectively, in Bologna in 1655-56 and in Florence in 1718), but was rehabilitated for the third edition printed in Padua in 1744. By that time, on the basis of the optical evidence of the earth’s revolution around the sun, Pope Benedict XIV had in fact led the Holy Office in allowing the publication of the Dialogo. However, it was only with the Index of 1757 that all heliocentric works were finally redeemed.


“My illustrious Lord, The obligation I have to serve you makes me feel the urgency to fulfill your order; so remembering that months ago you tasked me with finding a copy of Galileo’s Dialogo that was not to be found, I performed some research here and procured a copy, used though, of the Italian edition printed in Florence from the first ones [?]. Please let me know how I can let you have the book since given that the book is Prohibited I don’t trust the regular mail. I will make my return in October, since I have found things difficult […], if my Lord would do me the favour of the letter, it would be great, as this town requires the dependence of Lords, with Your Highness occupying the highest place among the prominent people. I revere my Lord as his humble servant. Venice, 29 August 1641. His devoted servant Francesco Albertinelli [?]”.


(Bifolium, 302x206 mm, written only on first leaf recto, traces of folding, very well preserved)

Please click here for a full description of this letter and the associated copy of Galileo’s Dialogo.

Fabrizio Govi